Improved powee-hammee



T. B. HARRISON.

POWER HAMMER.

No 68,740. Patented Sept. 10, 186'7.

Quinn 1am item; @ffm.

THOMAS B. HARRISON, 0F MAQ'UOKETA, ro s,

Letters Patent No. 68,740, dated September 10, 1867. i

flit? rlntnle admit it it ihseitrtters em: tut making part at tttsnmt. i i i Be it known that I, THOMAS B. HARRISON, of ,Maquoketa, in the county of Jackson, and State of Iowa, have invented a new and useful Power-Hammer; and I do hereby declarethat the following is afnll, clear, and exact description of the-same. reference being had to the annexed drawings, making a'part ofthis specification, in whicha 4 1 a Figure 1 is a perspective view, and

Figure 2 is a vertical section of the hammer, spring-box, and air-cylinder.

Figure 3 is a vertical side section of the air-cylinder, showing the cut-oh valve.

' Figure 4 is a front vertical section of the cut-off valve.

The construction of the machineis as follows: The hammer, marked H, in fig. 1, slides in vertical guides t G G' attached to the frame of the machine, and is fastened to the piston-rod A, which passes through the spring box S and into the air-cylinder Y, and is secured to the piston or follower fitting said cylinder. On the front and back of the cylindrical portion of the spring-boxS are two (2)-wrists, which are attached to the two (2) arms of the forked connecting-rods L L. The other end of the rod is connected tothe crank P, the .wrist of which is extended'to receive thesmall crank R. This is connected to the valve-rod N, and communicating a reciprocating motion to the arm 0 operating the adjustable cut off-valve W. The construction of the spring-box S is shown in section in fig. 2, and is a cylinder, having fitted to each end two cylindrical plugs or glands,V V, which are perforated to allow the piston-rod to pass through, and are secured to the spring-box S by means of the bolts FF]? F. In the interior of the spring-box is a circular diskor piston, T,firm1y attached to the pistonrod A, and fitting the inside diameter of the spring-box S. On the upperand lower surfaces of this piston are two annular projections, M M. In the upper and lower plugs V V are two corresponding grooves, filled with 'rubber, s0 as to form spring surfaces to receive the annular projections onthc piston T, the object being to prevent injury to the two spiral steel springs which are placed above and below the piston T.. The spiral springs are placed on the outside of the annular projections, on the upper and lower surfaces of the piston T. The above-mentioned annular projections are of sufiicient length to engage with the rubber springs C Gbefore the steel-springs are entirely compressed The air-cylinder Y, fig. 1, is bolted fast to the frame of the machine, and is provided with an ai'r-tight'pistun secured to the end of the piston-rod A. The cylinder is provided with an adjustable cnt-oif valve D. The construction of the cylinder is shown in section in fig. 3, together with aside vertical section of the cut-off. The air-cylinder is provided near the bottom with an opening, to allow the l V escape of the air from the cylinder through the air-passage B into the cut-oii' valve D. The cut-off valve D consists of a conical plug. This has an opening in the direction of its length, coinciding with the opening of the air-passage from the cylinder. This airpassage in the plug is bent downward at. a right angle, so as coincide with the openings in the shell U and the outer casing of the valve J, so as to permit the air to escape; readily from the cylinder when the valve is as the drawings 3 and represent it. The inside plug is accurately fitted to the valve-seat or' shell U, in which it has an oscillating motiori c ommunicatcd through the arm 0 and valve-rod N. The shell or valve-seat U can be moved, to any position by means of the. lever No. 7 in figs d and 4. The shell U has a mortise or opening extending through one-quarter of its circumference, as is scenrin the section, fig. 4. The object of this length of mortise is to allowthe inside plug II, when moved by means of the arm 0, shown by the dotted lines in fig. 4, to make its entire stroke without cutting cfi' or stopping the passage of air from the air-cylinder, when the shell is in the position indicated in fig. 4. But if the valve-seat U be turned round, by means of the lever 7 in fig. 4, the motion of the inside plug will out off the airfrom the cylinder at any portion of the stroke of the piston, the amount of cut-off being determined by the relative position of the air-passage in the plug H" and the air-way or mortise in the shell U.

The operation of the machine is as follows: When motion is communicated, by means of'apullcy and belt, or otherwise, to the crank, the connecting-rod raises the sprin'ghox. This compresses the lower spring against the plate or piston T, fig. 2, and through it lifts up the piston-rod A, lifting the hammer and forcing the piston to the top of the air-cylinder. If it is required to use the full force of the blow, the regulating lcvcr is placed in the position indicated in the section, fig. 4, and during the descent of the piston the air is allowed to escape freely. But if the blow is required to be lighter, the regulating lever is moved upward. This causes the motion of the valve to cut off the escape of the air from the cylinder at any required portion of the stroke. The air being condensed inthe air-cylinder Y, will form an elastic air-spring, lifting upwards on the piston-rod A, thus taking a portion of 'the blow off the hammer. If the lever 7.in fig. 4 be turned sufficiently around, so that the mortise in the shell U will be entirely beyond the stroke of the plug H, the air will becoudensed in the aircylinder during the entire stroke, and the hammer arrested in its descent, and will not touch the anvil face at all, thus allowing the workman to control the force of the blow at will;

The spring-box S is 'made sufiiciently long to allow the plugs or glands V V suflicient motion in the cylinder to compensate for the difi'erence of stroke or lift of hammer required for various thicknesses of the work to be forged. If the work is very thick the lower nuts on the boltsFFm'e screwed upwards, the upper nuts loosened upwards in the same proportion. The hammer will be raised, and a reverse motionto the screws will lower the hammer for light work.

I claim 1. The-cut-ofi' valve D, consisting of the plug H, shellU, and easing J, in combination with the air-cylinder Y, arranged and operating as described.

2. Theeombiimtionof thespring-box S, spiral springs, piston T, and rubhersprings C C,.arranged and operating as described v 3. The combination of the fixed air-cylinder Y with thepiston-rod A, spring-box S, forked connecting-rod Mid crank P, constructed and operated substantially as describe THOS. B. HARRISQN.

Witnesses:

D; R. Gnocnm, F. E. BAGHELDER. 

